LOS ANGELES — The stakes are high, the tactics are fierce, and the rhetoric is heating up.

Obama versus Romney? Nope. It’s the contest between ‘‘The Voice’’ and ‘‘The X Factor,’’ which escalated after NBC abruptly moved to pit its ‘‘Voice’’ against Wednesday’s second-season debut of Fox’s ‘‘X Factor.’’

The two singing contests already faced a tussle over audience votes when NBC scheduled a fall cycle of ‘‘The Voice’’ after it proved itself as a solid spring performer.

Then, in a post-Labor Day surprise, an apparently mischievous NBC said it was expanding the show’s first week from Monday and Tuesday to include a third episode, which happens to air opposite the first hour of the ‘‘X Factor’’ bow at 8-10 p.m. Wednesday. Fox’s show also airs Thursday.

Suddenly, the battle of the talent shows is much more interesting.

Or make that infuriating, if you’re ‘‘X Factor’’ creator, executive producer, and judge Simon Cowell. Known for his creative critiques as an ‘‘American Idol’’ panelist (“You sound like a cat jumping off the Empire State Building”), Cowell took off the gloves when he told a teleconference last week that he was angry ‘‘because I think there’s a kind of gentleman’s agreement.’’

The implication: Networks can slap each other around by putting dramas and comedies head-to-head, but a talent show is in a class of its own, like PBS’s ‘‘Downton Abbey’’ but with a record contract and hot modern blondes named Christina, Britney, and Demi.

‘‘I think it’s mean-spirited, and I hope and I pray that it backfires on them, because it’s one of the best shows we’ve ever made,’’ Cowell said, adding that three consecutive nights of ‘‘Voice’’ is ‘‘too much’’ and viewers will choose ‘‘X Factor.’’

Season two represents a sophomore reboot for ‘‘X Factor,’’ which did well last season but failed to pull the 20 million viewers Cowell had predicted. Instead, it averaged about 12.6 million for its performance and results episodes, which Cowell saw as a ‘‘wake-up call’’ for how to handle the US version of his British hit.

“The Voice’’ averaged 15.9 million viewers last season.

‘‘I was a bit cocky,’’ Cowell said in a recent interview. ‘‘I was feeling bullish coming off the UK show. And I don’t think I really read the [American] market that well’’ and how a strong show could let ‘‘massive social network power’’ make it a hit.

So is ‘‘X Factor’’ sharper now that first-year judges Nicole Scherzinger and Paula Abdul are out and Britney Spears and Demi Lovato are in? Also gone is host Steve Jones, to be replaced before live episodes begin in November by a likely male-female duo yet to be chosen (Kevin McHale of ‘‘Glee,’’ Kelly Osbourne, and Khloe Kardashian are among rumored candidates).

Yes, said Cowell, with the new judges and new producers making a difference.

Spears and Lovato are “doing great,’’ according to Cowell. Spears . . . “has good taste, and from working with her, you can understand why she’s lasted so long in the industry.” As for Lovato, 20, she’s a ‘‘revelation,’’ he said. ‘‘She’s very smart, she’s a brat, and that’s probably why I like her.’’

NBC declined to comment. ‘‘Voice’’ executive producer Mark Burnett, who told TMZ last week that he was unaware of his show’s added night and that it never occurred to him the two shows would compete, didn’t respond to a request for comment.

Recently, Burnett pointedly noted that there are format changes for ‘‘The Voice,’’ but he’s sticking with original mentors Christina Aguilera, Cee Lo Green, Blake Shelton, and Adam Levine as long as they’re available — in obvious contrast to Cowell’s musical chairs.

‘‘Truly we’ve gotten so close with all these guys, and it really has become like a family,’’ Burnett said, explaining why he opened his Malibu home for a ‘‘Voice’’ news conference.